Researchers have sequenced the genome of the sterlet sturgeon (Acipenser ruthenus) to show that it has changed little over the course of millions of years.
The University of Würzburg's Manfred Schartl and his colleagues sequenced the sterlet sturgeon, which has 120 chromosomes, to find that it underwent a whole genome duplication event some 180 million years ago. As reported in Nature Ecology & Evolution, the sterlet sturgeon has remained tetraploid over the years and not returned to a diploid state like other animals that have undergone whole genome duplication events.
"Over this long time span, we would have expected the genome to change more profoundly because in tetraploid organisms gene segments are often lost, silenced, or acquire a new function over time," co-author Axel Meyer, an evolutionary biologist at the University of Constance, says in a statement.
The researchers note that sturgeon are also known for limited morphological changes over time, and they uncovered a low protein evolution rate. The rate of protein evolution of the sterlet is similar to that of the coelacanth or of sharks — two fish species that have been roaming the oceans almost unchanged for more than 300 million years as well," adds Leibniz Institute of Freshwater Ecology and Inland Fisheries' Matthias Stöck.